1. Technical Field of the Invention
This invention concerns a device for brewing beverages, whether in individual portions, or for several portions together. The invention is especially oriented towards brewing tea in all its variations, although the device can equally be used to brew other drinks as well.
2. Description of the Prior Art
Tea is conventionally prepared using a variety of methods. In addition to the temperature of the brewing water, the composition and quality of the tea and the ratio of tea to brewing water, the decisive and most important factor impacting on the quality of the flavour of the tea is always the duration of the brewing period. This is particularly true of black tea. Any tea-lover knows this and, when brewing tea, will pay great attention to the length of the brewing time. The disadvantage of having to concentrate on the brewing time, however, is that one has little opportunity to engage in other activities during this period.
Tea is usually prepared by inserting tea into a porous brewing element such as a hollow, perforated two-part tin receptacle hanging by a chain which is then suspended in the hot water in the tea glass or teacup. At the end of the desired brewing period, the brewing element is removed by the chain from the tea glass or teacup, and the tea is ready to be drunk. The brewing time is often monitored with an electronic kitchen timer of the type also used for boiling eggs or baking cakes, etc. The brewing time is set on the timer, whereupon the timer is started. At the end of the pre-set period, i.e. when the brewing time is over, the timer emits an audible signal and the brewing operation can be interrupted. If one does not happen to be in the immediate vicinity of the timer, however, the signal can go unheard, in which case the tea will unavoidably remain too long in the brewing water. Another method of preparing tea is to submerge a pre-packed paper tea bag in the drinking receptacle containing the hot water and then remove it at the end of the ideal brewing time. It is for this purpose that these tea bags are often attached to a thread at the end of which there is a label so that the thread can be hung over the edge of the drinking receptacle with the label outwards. Here, too, however, there has to be some means of monitoring the brewing time, and it is important to intervene immediately after the brewing time comes to an end, i.e. to remove the tea leaves from the brewing water, thereby concluding the brewing process. If one fails to monitor the brewing process carefully, or if one lets oneself be distracted, for example, the brewing time is often exceeded and the flavour of the tea suffers as a result. Nevertheless, it is irksome to have to concentrate specially on such an elementary operation as measuring the passage of time, and to have to simply wait inactive for the required amount of time to pass.
A remedy can be found in electric appliances which, amongst other things, allow the user to pre-set the brewing time, at the end of which the appliance automatically interrupts the brewing process. Electrical appliances, however, have several disadvantages: firstly, they require an electrical supply point, secondly, the mode of operation often requires explanation and can often be too complicated for people who do not use the appliance regularly, and, thirdly, they are expensive to purchase. And finally, electric brewing devices do not really fit with the image of the committed tea-drinker.
There have already been proposals for various non-electric devices for brewing beverages which stop automatically at the end of the brewing time. DE 29 04 569, for example, discloses a device for selecting the brewing time for hot drinks which has a floatable tea container inside the brewing receptacle and an anchoring element at the bottom of the brewing receptacle which counteracts the buoyant force exerted on this tea sieve float. An actuating element that reacts to heat, e.g. expanding bellows or a bimetal, releases the anchor, whereupon the floatable tea container rises up, thereby separating the material requiring brewing from the liquid. It has, however, proved costly to manufacture a reliably working actuating element.
WO95/07648 discloses a beverages brewing method for preparing cup-sized portions of coffee in coin-operated machines. The method works with two containers positioned inside each other and at a distance from each other, with the top one having a double bottom made from filter material, between which ground coffee is enclosed, and the other one serving as a disposable cup. The hot water runs through the filter material and the ground coffee trapped inbetween, and drips into the cup. When the liquid level reaches the filter material, the top container begins to float until a hydrostatic balance is achieved between the hot water in it and the coffee in the cup, and hence outside the top container. This method is intended to be used for automatic dispensing machines and is not suitable as a simple device for preparing individual cups of tea, e.g. at home or at work.
Based on this state of the art, the invention is based on the object of creating a simplified device for brewing beverages. Firstly, with this device there should be no need to intervene at the end of the brewing time, because the brewing process should stop automatically, so that, once the brewing process has been started, one can leave the device on its own without running the risk of allowing the brewing process to go on for too long. Furthermore, it should also be possible to pre-set different brewing times, and the structure and mode of operation of the device should be as simple as possible so that the way it functions is selfexplanatory, and can be understood immediately by everyone.
The foregoing and related objects are achieved by the present invention, which provides a device for brewing beverages comprising a brewing receptacle and an associated brewing sieve in the form of a porous holder for the material requiring brewing. The invention includes mechanical-hydraulic means for automatically and adjustably ending the brewing process. These means comprise a holder, which has a lighter specific weight than water, and which can be introduced into the brewing receptacle, as well as a weighing-down element, by which the holder for the material requiring brewing can be kept submerged in the brewing liquid in the brewing receptacle for a pre-set length of time. The weighing-down element includes an upwardly open container filled with water, which rests on the holder and has an opening at the bottom through which the water in the weighing-down element can flow into an insert ring. As soon as the upwardly open container, and hence the holder, as well, are relieved of the weight of the water in container, the holder begins to rise up and lifts the material requiring brewing out of brewing liquid.